An “X” capacitor or “X-cap” may generally be coupled between line and neutral inputs of an AC voltage source of a switching power supply. An X capacitor may be configured as a safety capacitor, e.g., to suppress electromagnetic interference (EMI), such as differential mode (DM) noise. However, the capacitance of an X capacitor may be too large to timely discharge in some cases. When the AC voltage source is “cut-off”, or otherwise turned off or disconnected, energy may remain stored in the X capacitor, and this may fail to meet various safety standards. In one example standard, the voltage between input terminals of an AC voltage source must decrease to 30% of the rated voltage within two seconds after the AC voltage source is cut-off. Thus, the X capacitor must be at least partially discharged after the AC voltage source is cut-off to meet such a safety standard.